Add strict buffer parsing index check to avoid the following Smatch warning:
net/core/pktgen.c:877 get_imix_entries() warn: check that incremented offset 'i' is capped Checking the buffer index i after every get_user/i++ step and returning with error code immediately avoids the current indirect (but correct) error handling. Reported-by: Dan Carpenter <dan.carpen...@linaro.org> Closes: https://lore.kernel.org/netdev/36cf3ee2-38b1-47e5-a42a-363efeb0ace3@stanley.mountain/ Signed-off-by: Peter Seiderer <ps.rep...@gmx.net> --- net/core/pktgen.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/net/core/pktgen.c b/net/core/pktgen.c index e850598db3e7..fe7fdefab994 100644 --- a/net/core/pktgen.c +++ b/net/core/pktgen.c @@ -856,6 +856,9 @@ static ssize_t get_imix_entries(const char __user *buffer, if (pkt_dev->n_imix_entries >= MAX_IMIX_ENTRIES) return -E2BIG; + if (i >= maxlen) + return -EINVAL; + max = min(10, maxlen - i); len = num_arg(&buffer[i], max, &size); if (len < 0) @@ -869,6 +872,8 @@ static ssize_t get_imix_entries(const char __user *buffer, if (c != ',') return -EINVAL; i++; + if (i >= maxlen) + return -EINVAL; if (size < 14 + 20 + 8) size = 14 + 20 + 8; @@ -911,6 +916,9 @@ static ssize_t get_labels(const char __user *buffer, if (n >= MAX_MPLS_LABELS) return -E2BIG; + if (i >= maxlen) + return -EINVAL; + max = min(8, maxlen - i); len = hex32_arg(&buffer[i], max, &tmp); if (len < 0) -- 2.48.1
